Method for performing a percutaneous diskectomy using a laser

ABSTRACT

A method for performing percutaneous diskectomy using a laser applies a laser beam from the laser to vaporize nucleus pulposus in the nucleus of the herniated disc. The wavelength of the laser beam will vary and depend on the laser system used.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method for vaporizing nucleus pulposuswithin a lumbar disc of the vertebral column during a percutaneousdiskectomy procedure using a laser.

2. Description of the Prior Art

Mechanically assisted percutaneous lumbar diskectomy of the prior art isused as a treatment of leg pain (sciatica) resulting from herniateddiscs of the lumbar vertebral column. The lumbar vertebral columnconsists of five vertebrae extending superiorly to the transitionalthoracic vertebrae (1) at a first end and extending inferiorally to thesacrum (3) at a second end, as illustrated in FIG. 1. Between eachlumbar vertebrae and between the lumbar and sacrum are cartilaginousdiscs. Each disc comprises an outer circular structure (annulusfibrosus) 2 which surrounds and tightly binds an inner gelatinousmaterial (nucleus pulposus) 4 in the center, as illustrated in FIG. 2.The annulus fibrosus 2 is made up of concentric fiberts which appear tocross each other obliquely. No blood vessels or nerves penetrate thenucleus.

Usually with age, the fibers of the annulus begin to degenerate. Thedegeneration results in the tearing of individual fibers when thevertebral column is stressed. Torn fibers can form fenestrations whichallow the nucleus pulposus to move through the fibers of the annulus andbulge 5 outward away from the nucleus. If the bulged disc presses uponan adjacent nerve root 6, sciatica may develop, as illustrated in FIG.3A.

It has been demonstrated that removing a portion of the nucleus withgrasping forceps through a small cannula will produce good to excellentrelief of pain in a majority of patients having symptoms indicative ofsciatica. Once a portion of the nucleus is removed, the pressure againstthe nerve root causing the pain is relieved as the remaining nucleuscontracts away from the pressure point, as illustrated in FIG. 3B.Hijikata S., Yamagishi M., Nakayama T., Oomori K., "PercutaneousDiskectomy: A New Treatment for Lumbar Disc Herniation", J. TodenHospital 1975; 5:5-13. Since the Hijikata et al. article, mechanicalforceps for microlumbar and percutaneous lumbar diskectomy procedureshave been developed related to relieving sciatica pain.

U.S. Pat. No. 4,369,788, which issued in Jan. 25, 1983 to Goald teachesone such forceps device having an alligator jaw for microlumbar discsurgery. The forceps can be held by a surgeon in a reversed backhandgrip which aids in their manipulation during microlumbar disc surgeryprocedures. For microlumbar disc surgery, a one-inch incision is made inthe patient into which the forceps are inserted and the surgery isperformed.

U.S. Pat. No. 4,545,374, which issued on Oct. 8, 1985 to Jacobsonteaches a method and instruments for performing percutaneous diskectomy.The instrumentation taught by Jacobson is illustrated in FIGS. 4-10 andincludes a speculum 20 which has a pair of semi-sharp edged blades 21for piercing and stretching body tissue and pivotally hinged handles 22for opening and closing the blades, as illustrated in FIG. 4. Speculum20 has a guide means for guiding the speculum along a slender membersuch as a spinal needle (not shown) having a diameter of less than 3millimeters. The guide means can be any form of a bore or hole throughwhich the spinal needle can pass. Jacobson also teaches a cannula 30,which is illustrated in FIG. 5. Cannula 30 is a cylindrical tool havinga bore 32 for passing instruments therethrough from outside the body toinside the body. Cannula 30 has an oval cross section for allowingdifferent sized and shaped instruments therethrough. Cannula 30 also hasanchor means for anchoring the cannula to the disc. Jacobson teachesusing a trocar 40 which is inserted into cannula 30, as illustrated inFIGS. 6 and 7. Trocar 40 has a shaft 41 and a collar 42. Shaft 41 fitsinto hole 32 of cannula 30 to a point where collar 42 is located. Collar42 is adjustable, thereby allowing shaft 41 to be adjustably inserted atdifferent lengths into hole 32. Shaft 41 of trocar 40 is tapered at oneend to a point 45 for anchoring into body tissue. A knife 50, asillustrated in FIG. 8, having a blade end 53, 54 and a handle 51 at anopposite end to the blade end is insertable through cannula 30. Bladeend 53, 54 is curved to allow quick and more efficient fragmentation ofdisc nucleus pulposus because it undergoes a curved cutting path duringuse. Rongeur forceps 60 for removing fragmented disc nucleus materialare inserted into the cannula after knife 50 is removed. Rongeur forceps60 have scissor-like handles 61, 62 pivotally connected near one end bypivot 63 and a jaw 68, 69, wherein spreading the handles 61, 62 opensthe jaw 68, 69 and squeezing the handles 61, 62 closes the jaw 68, 69,as illustrated in FIG. 9.

The percutaneous lumbar diskectomy procedure taught by Jacobson includesplacing a patient in a lateral decubitus position on an operating table;anesthetizing the patient usually with a long spinal needle which isguided into the disc area with the aid of fluoroscopic x-ray; incising a1 centimeter long skin incision to create a percutaneous channel 9 witha speculum 20, as illustrated in FIG. 10. Speculum 20 is constructed toopen and close and has jaw blades with semi sharp edges which spreadrather than cut body tissue. Guiding speculum 20 by guide means overspinal needle 24 until properly located; spreading the jaws of speculum20 open to create channel 9 for the insertion of cannula 30 to act as aconduit for the insertion of tools; inserting cannula 30 with the aid ofa trocar 40 and removing speculum 20. Trocar 40 adds stiffness to theflexible cannula and eases its insertion along with the guidance offluoroscopic x-ray. Trocar 40 can have pointed tip 45 which sticks intothe disc capsule 8 and prevents lateral movement of cannula 30. Passinga nerve stimulator 80 (not shown) down channel 9 with cannula 30 ortrocar 40. Stimulator 80 will cause motion in one of the patient's legsif it makes nerve contact, thereby signaling the surgeon that a slightlydifferent insertion position is necessary. Cutting a hole in the annulusfibrosus surrounding the nucleus with knife 50 or another trocar havinga rotatable reamer; fragmenting the nucleus pulposus with knife 50,ultrasonics, laser or dissolving chemicals; removing fragments ofnucleus pulposus with Rongeur forceps 60 and/or suction. Rongeur forceps60 preferably have large angled jaws which sweep a wide arc and severalRongeur forceps may be used each with slightly different angled jaws toremove nucleus pulposus from different portions of the disc. The surgeonuses rotational motion about an axis defined by the shaft of the forcepsin order to scoop out material about an axis of revolution. A Z-headRongeur forceps can create a cavity of revolution by removing a largeamount of nucleus material upon rotation. Flushing the cavity created inthe nucleus pulposus with saline solution to clean out the space;suctioning out the solution and any debris contained therein; removingthe cannula and stitching up the fat and fascia underneath the skin; andbandaging the outer skin surface with an adhesive strip to preventsuture scars.

Jacobson taught that this procedure requires one to two days recoverytime, that outpatient convalescence is possible and that the totalprocedure time is approximately 15 minutes. Nevertheless, theinstrumentation and procedure require extensive manipulation of tools bythe surgeon, that a more streamlined procedure using fewer tools wouldbe desirable. In practice, the Jacobson procedure has a 60% failure ratein relieving back pain and takes greater than 15 minutes to perform.

U.S. Pat. No. 4,678,459 issued to Onik et al. on July 7, 1987 teachesusing an irrigating, cutting and aspirating system for percutaneoussurgery. Onik et al. teaches using a system for removing nucleuspulposus tissue 79 which includes a probe and a guillotine type ofcutting means 78 for cutting the nucleus pulposus 79, as illustrated inFIG. 11. The severed or cut fragments of nucleus pulposus 79 are removedfrom the cutting means 78 using an internal fluid irrigation system anda vacuum to aspirate the severed fragments out of the disc area, throughthe system, and out of the patient. This system provides for arelatively fast diskectomy procedure compared to the other prior artbecause nucleus pulposus can be fragmented and removed without the needto manipulate many small blades, knives and forceps, as described forthe Jacobsen U.S. Pat. No. 4,545,374. The probe and guillotine-typecutting means taught by Onik et al. is sold on the market as aNucleotome Probe 70, as illustrated in FIG. 15. This instrument is themost widely used instrument for percutaneous diskectomy. The procedureand instrumentation used to implement the Nucleotome Probe 70 includeplacement of a FlexTrocar 71 into a 3 millimeter skin incision made onthe side of the patient's body where the herniation is evident. TheFlexTrocar 71 is inserted until it contacts the annulus fibrosus 72 ofthe herniated disc, as illustrated in FIG. 12, using the guidance of afluoroscopic X-ray. Once the FlexTrocar 71 is in place, a straightcannula 73 having a tapered dilator 74 is passed over the FlexTrocar 71and inserted down to the annulus 72 wall, as illustrated in FIG. 13. Theposition of the straight cannula 73 is confirmed fluoroscopically. Oncethe cannula 73 is in place, the tapered dilator 74 is removed from thecannula 73. A trephine 75 is inserted through the cannula 73 and overthe FlexTrocar 71. The trephine 75 is rotated in a clockwise motion withslight pressure to incise the annulus, as illustrated in FIG. 14. Thetrephine 75 and the FlexTrocar 71 are subsequently removed from thepatient's body. The Nucleotome Probe 70 is inserted into the cannula 73after the trephine 75 and FlexTrocar 71 are removed. The NucleotomeProbe 70 locks into place on the cannula 73, as illustrated in FIG. 15.When the Nucleotome Probe 70 is activated, the nucleus pulposus is cutinto fragments which are removed with irrigation fluids and suction, allwithin the Nucleotome Probe 70. The Nucleotome Probe 70 is activateduntil no further material can be extracted. Once complete, theNucleotome Probe 70 and cannula 73 are removed and the entry point iscovered with a sterile bandage. The cutting and extracting process aloneusing the Nucleotome Probe 70 normally takes between 20 to 30 minutes.

In 1989, P. W. Ascher, D. S. Choy and H. Yuri suggested using lasers tovaporize disc material in a percutaneous diskectomy procedure. Ascher etal. believed the CO₂ laser was not a viable choice for percutaneousdiskectomy because an optical fiber for the CO₂ laser was not yetavailable. Ascher et al. reported using an Nd:YAG laser at 1060 nm sincean optical fiber was available. Ascher et al. were aware that the Nd:YAGlaser at 1060 nm had low absorption in water and white tissue and highabsorptivity in water and white tissue is necessary to produce effectivevaporization of nucleus pulposus. Tests were performed with less thanencouraging results. Also, Ascher et al. reported using a Nd:YAG laserat 1320 nm and claimed it produced twice as much volume reduction ascompared to the 1060 nm laser. Nevertheless, Ascher et al. reported thatonly the CO₂ laser, or the Er:YAG laser would produce sufficient resultsin about 10-15% of patients having the requisite symptoms. Abstract No.202, p. 48, entitled "Percutaneous Nucleus Pulposus Denaturization andVaporization of Protruded Discs", American Society for Laser Medicineand Surgery: Lasers in Surgery and Medicine, Supplement 1, 1989.

The results of the Ascher et al. investigations did not produce safe andeffective results using a laser to vaporize nucleus pulposus fromherniated discs. It would be desirable if a laser technique and laserinstrumentation were available to perform percutaneous diskectomies sothat nucleus pulposus from herniated discs could be vaporized using alaser in a safe and effective way which is faster than cutting andirrigating using the Nucleotome Probe and which would eliminate the needto cut and remove fragmented debris from the patient.

SUMMARY OF THE INVENTION

Therefore it is an object of the present invention to provide a methodfor performing percutaneous diskectomy using a laser in a safe andeffective manner.

According to the object of the present invention a method for performingpercutaneous diskectomy using a laser comprises applying a laser beamfrom the laser to a herniated disc area, the laser beam having awavelength in the range of 350 through 1000 nm. The wavelength of thelaser beam applied to the herniated disc according to the presentinvention will vary and depend on the laser system used.

A safe manner of performing a percutaneous diskectomy using a laser isdefined as using a laser system which vaporizes the target material withminimal thermal damage to adjacent structures. An effective manner ofperforming a percutaneous diskectomy using a laser is defined as using alaser system which sufficiently vaporizes the target material to relievethe pain at least caused by sciatica.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a posterior view of the lumbar vertebral column.

FIG. 2 is an oblique view of a lumbar disc and inferior vertebrae.

FIG. 3A is a sectional view of a herniated lumbar vertebrae and anassociated nerve root.

FIG. 3B is a sectional view of the vertebrae in FIG. 3A after nucleuspulposus is removed.

FIG. 4 is a side view of a prior art speculum.

FIG. 5 is a oblique view of a prior art cannula.

FIG. 6 is a side view of a probe of the prior art.

FIG. 7 is a side view of the probe in FIG. 6 inserted into the cannulaof FIG. 5.

FIG. 8 is a side view of a knife of the prior art.

FIG. 9 is a side view of a prior art Rongeur forceps.

FIG. 10 is a sectional view of a channel created by the prior artspeculum in FIG. 4.

FIG. 11 is an exploded sectional view of the Nucleotome Probe of theprior art.

FIG. 12 is an oblique view illustrating FlexTrocar of the prior artentering the disc area.

FIG. 13 is an oblique view illustrating straight cannula and tapereddilator of the prior art.

FIG. 14 is an oblique view illustrating the trephine of the prior art.

FIG. 15 is an oblique view illustrating the Nucleotome Probe of theprior art.

FIG. 16 is a posterior view of a patient in a lateral decubitusposition.

FIG. 17 is a side view illustrating a probe used with the presentinvention.

FIG. 18 is an oblique view illustrating the probe inserted into a discaccording to the present invention.

FIG. 19 is a sectional view of a herniated disc and associated nerveroot having the probe inserted thereinto according to the presentinvention.

FIG. 20 is a side view of a cannula having a dilator inserted thereintoused with the present invention.

FIGS. 21A-21E are sectional and plan views of a bayonet type lockfitting used with the present invention.

FIG. 22 is a side view illustrating a curved cannula used with thepresent invention.

FIG. 23 is a side view illustrating an introducer means according to thepresent invention.

FIG. 24 is a side view illustrating a stylet used with the presentinvention.

FIG. 25A-H are sectional views illustrating a clamping means accordingto the present invention.

FIG. 26 is a side view illustrating an introducer means having a formedend according to the present invention.

FIG. 27 is an exploded sectional view illustrating an optical guidingmeans emanating from the formed end of introducer means according to thepresent invention.

FIG. 28 is a side view of an irrigation/aspiration cannula used with thepresent invention.

FIGS. 29A-C are sectional views illustrating a position indicator meansaccording to the present invention.

FIGS. 30A,B are plan views illustrating the first line of a laser beam.

FIGS. 31A-C are plan views illustrating the second line of a laser beam.

DETAILED DESCRIPTION OF THE INVENTION

A percutaneous diskectomy procedure using a laser is designed forpatients commonly showing evidence clinically and radiologically ofnerve root impingement. Conventionally, physical examination of thepatient should reveal leg pain greater than back pain and signs of nerveroot irritation consistent with a herniated disc. Radiographically, thepatient should exhibit a focal herniation or bulge that shows animpression on the thecal sac which does not occupy more than fiftypercent of the thecal sac. Also, the radiographic results shouldcorrelate with the patient's symptomatology.

Vaporization of nucleus pulposus material according to the presentinvention suggests that the operative tools be inserted at an entry siteon the same side of the patient's body that the herniation or otheraffliction is evident. The path of entry to the afflicted disc shouldavoid going through the psoas muscle since the lumbar plexus hasnumerous fibers which traverse the muscle. Conventionally, a computedtomograph (CT) scan slice of the whole abdomen through the involved discis quite helpful for determining the entry path.

The safety of the procedure relies on radiologic localization andguidance of the instruments into the disc and a C-arm fluoroscope withimage intensification, known in the art, can provide clear and sharpimages in anteroposterior, lateral and oblique views.

Typically, the patient undergoing a percutaneous diskectomy procedure ispositioned on a fluoroscopic table, which is known in the art, in alateral decubitus position, as illustrated in FIG. 16. The patient mustbe stabilized to prevent rotation of the patient's shoulders and hipsduring the procedure. Using a fluoroscope, the sacrum is identified andlocated, the afflicted disc is located, and as illustrated in FIG. 16, aposterolateral entry point is selected. The entry point typically is8-12 centimeters from the midline and both parallel and midway betweenthe end plates of the afflicted disc, as determined using a measuringscale. Local anesthetic is used to anesthetize the area to be operatedon which is administered typically with a long spinal needle.

At this point in the patient preparation procedure, the percutaneousdiskectomy procedure using a laser and means for insertinginstrumentation according to the present invention is described.

First, one end of a semi-rigid trocar or probe 100, which is preferably18 gauge Birmingham Wire Gauge (BWG), is inserted at the entry pointonce the anesthetic has taken effect. Probe 100 has an elongated body100a and has a standard tube clamp 100b with a threaded lock 100cconnected 26 to probe 100, as illustrated in FIG. 17.

Clamp 100b is removable from body 100a by loosening lock 100c andsliding clamp 100b in either direction beyond the end of probe 100.Clamp 100b serves as a handle to hold probe 100 while it is insertedinto the patient. Clamp 100b is removed for subsequent steps describedbelow. Clamp 100b may be made of plastic, for exampleacrylonitrile-butadiene-styrene (ABS) plastic or preferablypolycarbonate plastic, or metal, preferably stainless steel.

Probe 100 is preferably made of stainless steel also, for example type304 or an equivalent, No. 3 temper. The inserted end of probe 100 has asharp tip and is guided into the damaged or herniated disc area 18c withradiologic localization and guidance, preferably using the C-armfluoroscope with image intensification, as described above. Probe 100 isinserted until the inserted end punctures through the annulus fibrosus18a of the disc 18b, as illustrated in FIGS. 18 and 19. While probe 100is in place, extending from the disc area to outside the patient's body,a cannula 104 having a dilator 102 inserted thereinto is inserted overprobe 100 at the exterior end and into the probed disc area 18c. One endof dilator 102 (102b) and cannula 104 (104b) remain on the exterior ofthe patient.

Cannula 104 and dilator 102 are preferably 12 gauge stainless steeltubing, for example type 304, No. 3 temper (full hard). Stainless steeltubing may be purchased at any stainless steel tubing supplier, forexample Poper and Sons, N.Y. Dilator 102 preferably is longer thancannula 104 and has a tapered end 102a which extends beyond the end 104aof cannula 104, as illustrated in FIG. 20, for ease of insertion overprobe 100 through the patient's skin. Dilator 102 has bore 102d whichextends through the center of dilator 102 along its length. Probe 100fits within bore 102d of dilator 102. Cannula 104 is preferably astraight tubular member having a central bore 104d, which extends alongits length. Dilator 102 and probe 100 fit within bore 104d of cannula104.

Cannula 104 and dilator 102 have locking means 103 (103 mechanism notshown) for locking dilator 102 to cannula 104 at end 104b and 102b,respectively, and a locking stabilizer 105, as illustrated in FIG. 20.Locking means 103 is preferably a bayonet-fitting locking mechanism, asillustrated in FIGS. 21A-21F. Dilator 102 has portion 103a and cannula104 has portion 103b of bayonet-fitting locking mechanism 103. Portion103b on cannula 104 has a segmented body and flared legs for grippingand preferably projection 103b-1 having two laterally extending flanges103b-2 which oppose one another. Portion 103a on dilator 102 preferablyhas aperture 103a-1 and sockets 103a-2. Aperture 103a-1 is at least asdeep as the distance projection 103b-1 projects. Sockets 103a-2oppositely extend off aperture 103a-1 and are at least as deep asflanges 103b-2 are thick. Projection 103b-1 and flanges 103b-2 fitwithin aperture 103a-1 and sockets 103a-2, respectively. Once fittedtogether, end 102b of dilator 102 is turned clockwise thereby rotatingdilator 102 within cannula 104 to lock locking portion 103a to lockingportion 103b and thereby lock dilator 102 to cannula 104 using lockingmeans 103. Locking means 103 can also be a luer lock, threaded screwlock, snap lock or a friction fitted lock, which are known in the art.Locking means 103, and stabilizer 105 can be made of plastic, ABS orpreferably polycarbonate plastic, or metal, preferably stainless steel.In the preferred embodiment, means 103, ends and stabilizer 105 are madeof a plastic which can withstand at least the stresses associated withgamma sterilization techniques without distortion. The plastic may alsowithstand the stresses associated with autoclaving and usage of ethyleneoxide gas sterilization methods. Locking stabilizer 105 is adjustablylocated along the length of cannula 104 and serves to rest against thepatient's skin when the cannula is properly placed.

In another embodiment, curved cannula 106 may be inserted into thepatient instead of straight cannula 104. Cannula 106 is a curved tubularmember having a locking dilator 107 and locking stabilizer 108, asillustrated in FIG. 22. Curved cannula 106 is used in situations wherethe patient's afflicted area is within the lumbar 5-sacrum 1 region ofthe vertebral column, as shown in FIG. 1.

Once dilator 102 and cannula 104 are confirmed, preferablyfluoroscopically, to be embedded in the annulus fibrosus, dilator 102 isunlocked from locking mechanism 103 and removed. Dilator 102 is unlockedby turning portion 103a counterclockwise while holding portion 103b oncannula 104 stationary. As dilator 102 is withdrawn, cannula 104 isadvanced forward to embed in the wall of the annulus approximately thedistance equal to the difference in length of dilator 102 and cannula104. Cannula 104 is secured by stabilizer 105 by unlocking the screwmechanism, sliding stabilizer 105 up against the patient's skin, andlocking the screw. Probe 100 is removed once cannula 104 is secured.

Second, one end of a first introducer means or tube 110 for insertinginstrumentation according to this invention is inserted into centralbore 104d at the exterior end 104b of cannula 104. First introducermeans 110 is a substantially straight elongated member preferably 14gauge along most of its length and having a 17 gauge tip 110a at oneend, as illustrated in FIG. 23, and a clamping means 111 at an oppositeend for clamping to an optical guiding means, as is described below.First introducer means 110 is metal, preferably type 304 stainlesssteel, No. 3 temper (full hard). Clamping means 111 can be plastic,preferably polycarbonate plastic or metal, preferably stainless steel.First introducer means 110 has a bore 110d (not shown) which extendsthrough the center of first introducer means 110 along its length.

When the one end 110a of first introducer means 110 is inserted intobore 104d of cannula 104, first introducer means 110 preferably has astylet 112 extending therethrough. Stylet 112 is a long straight member,preferably 18 gauge stainless steel, having a sharp tip 112a at one endand a handle means 112b for handling stylet 112 at the opposite end, asillustrated in FIG. 24 The sharp end 112a can be a conical-shaped tip,diamond shaped tip or beveled, for example. Sharp end 112a extends outof the inserted end 110a of the first introducer means and stylet 112locks into clamping means 111 on first introducer means 110 at handlemeans end 112b. The locking mechanism for clamping means 111 will bedescribed below. Sytlet 112 is longer than and narrower in diameter thanfirst introducer means 110 and fits within bore 110d of first introducermeans 110. The clamping means 111 can also lock with handle means 112beither with a luer lock, threaded screw lock, snap lock, friction fit,but clamping means 111 is preferred.

Because the sharp tip extends out of the inserted end 110a of firstintroducer means 110, stylet 112 contacts the outer wall of the nucleus18d and enters into the nucleus with its sharp tip 112a, leaving a smallopening. Since the nucleus is a soft gelatinous material, stylet 112enters the nucleus with minimal resistance and the inserted end 110a offirst introducer means 110 is placed in the nucleus. Stylet 112 isremoved from the nucleus through the first introducer means 110, and thefirst introducer means or tube 110 is left in place for introducinginstrumentation into the nucleus. One end of a first optical guidingmeans 116 for guiding laser light is inserted through bore 110d of firstintroducer means after stylet 112 is removed. First optical guidingmeans 116 is inserted until it emanates from end 110a of firstintroducer means into the small opening made by stylet 112.

First optical guiding means 116 is preferably an optical fiber or ahollow optical wave guide, depending on the embodiment. In a firstembodiment, the optical fiber is used which is preferably 400micrometers in inner diameter and 600 micrometers in outer diameter andis made of quartz. In the second embodiment, the hollow optical waveguide is used which can be made from metal or ceramic and is preferablymade of ceramic. The hollow waveguide is rigid compared to the opticalfiber.

First optical guiding means 116 comprising either the optical fiber ofthe first embodiment or the hollow optical waveguide of the secondembodiment passes through first introducer means 110 and into thenucleus 18d at a first end and is connected to a first laser means forproducing laser light at a second end outside of the patient. Firstoptical guiding means 116 preferably has a position indicator means 111hfor indicating a preset distance optical guiding means 116 must extendout of first introducer means 110 at end 110a. Positioning indicatormeans 111h, which is described below, is illustrated in FIGS. 29A-C andserves to prevent optical guiding means 116 from being inserted beyondthe preset distance by contacting clamping means 111 from one end.

Clamping means 111 then locks optical guiding means 116 in place infirst introducer means 110. Clamping means 111 serves to ensure thatoptical guiding means 116 moves with first introducer means 110 as firstintroducer means 110 is manipulated during the diskectomy procedureaccording to the preferred embodiment.

As illustrated in FIG. 25A, clamping means 111 has a clamping end 111a,midsection 111b and an introducer end 111c. Midsection 111b andintroducer end 111c preferably comprise clamp housing 111g. Clampingmeans 111 can be made of a metal, for example stainless steel, but ispreferably made of molded plastic, preferably polycarbonate plastic.Clamping end 111a comprises a clamp 111a-1 having a clamping head111a-2, two integrally connected compression legs 111a-3, and sidemembers 111a-7, as illustrated in FIGS. 25A-C. Side members 111a-7 arewider than compression legs 111a-3. Clamping head 111a-2, side members111a-7, and compression legs 111a-3 are preferably molded as one piece.Legs 111a-3 and side members 111a-7 are integrally connected to head111a-2 at one end while the opposite ends are free.

Compression legs 111a-3 and side members 111a-7 of clamp 111a-1 fitwithin midsection 111b of housing 111g, and each compression leg 111a-3has a cylindrical boss 111a-4 which projects laterally therefrom, asillustrated in FIGS. 25A-F. Bosses 111a-4 fit within internal curvedrecesses 111b-1 of midsection 111b as illustrated in FIG. 25G when clamp111a-1 is fully inserted into housing 111g. Curved recesses 111b-1 serveas cam surfaces while the cylindrical bosses 111a-4 serve as camfollowers. Compression legs 111a-3 also each have an engagement ear111a-5 at the free ends thereof. Engagement ears 111a-5 projectlaterally out and fit within retention slots 111b-2 in outer housing111g, as illustrated in FIGS. 25A-F. Retention slots 111b-2 are locatedin midsection 111b near where midsection 111b and introducer end 111cmeet. As clamp 111a-1 is inserted into housing 111g, bosses 111a-4 slidealong recesses 111b -1 until engagement ears 111a-5 snap into retentionslots 111b-2, thereby fixing the assembly together, as illustrated inFIG. 25A. Then housing 111g is rotated while clamping end 111a is heldstationary, causing midsection 111b to press in on compression legs111a-3 with cam and follower action. Engagement ears 111a-5 also moveout of retention slots 111b-2 and within midsection 111b as midsection111b is rotated.

An elastomer 111d is retained by the inner radius of compression legs111a-3 and side members 111a-7 and is preferably tubular in shape,extending from head 111a-2 to engagement ears 111a-5, as illustrated inFIG. 25A. Elastomer 111d is a resilient material, preferably siliconerubber. Elastomer 111d grips or clamps to optical guiding means 116 whenhousing 111g is rotated. Optical guiding means 116 is inserted intofirst introducer means 110 through bore 110d to a position indicated byits position indicator means 111h, as illustrated in FIGS. 29A-C.Optical guiding means 116 is intended to extend out of end 110a for adistance, which is determined by the surgeon to be within the nucleus18d of the afflicted disc 18b. Compression legs 111a-3 compresselastomer 111d against optical guiding means 116 in the fully rotated,locked position. The side members 111a-7 prevent radial expansion of theelastomer 111d during the compression. Elastomer 111d grips and preventsaxial slippage of optical guiding means 116. The compressed elastomer111d distributes the clamping force on the optical guiding means in sucha manner that the optical transmission characteristics of opticalguiding means 116 are not degraded. In addition, elastomer 111d exhibitsa large coefficient of friction against optical guiding means 116. Thislarge coefficient of friction minimizes the clamping force required tosustain a given degree of restraining force. Because of thecharacteristics of elastomer 111d, clamping means 111 is also removableby rotating housing 111g in the opposite direction to release thecompression forces without degrading the optical guiding means 116optical characteristics.

Both clamping means 111 and position indicator means 111h clamp and griponto optical guiding means 116 in the same way and clamping means 111also clamps to stylet 112 in the same fashion. The shapes of housing111g and position indicator means (111h) differ although they comprisesimilar components. The differences in housing 111g and the housing111h-1 of position indicator means 111h relate to introducer end 111c.Introducer end 111c is shaped to fit and grip end 110b of firstintroducer means 110. End 110b is flared as illustrated in FIG. 25A andflare grip 111c-1 holds end 110b in place. In the preferred embodiment,flared end 110b is bonded into introducer end 111c using an organicadhesive, for example fast bonding adhesives which are compatible withboth plastics and metal, like cyanoacrylate adhesives. On the otherhand, position indicator means 111h is shaped to facilitate theinsertion of the optical guiding means 116, which does not have flaredends, as illustrated in FIGS. 29A-C.

Clamping means 111 is assembled as follows: First, end 110a of firstintroducer means 110 is inserted into housing 111g from midsection 111bend until flared end 110b contacts with flared grip 111c-1. End 110b offirst introducer means 110 is held in place until bonded with apre-applied adhesive Second, elastomer 111d is then inserted within theinner radius of compression legs 111a-3. Third, clamp 111a-1 is insertedinto midsection 111b until engagement ears 111a-5 engage with retentionslots 111b-2. Housing 111g is not rotated into the clamping positionuntil optical guiding means 116 or stylet 112 is inserted and clampingis necessary.

Fourth, using laser energy from the laser means through first opticalguiding means 116, some of the nucleus pulposus within nucleus 18d isvaporized to create a first vaporized area in the nucleus 18d of theherniated disc 18b. The first vaporized area provides a space or cavityin the nucleus pulposus into which nucleus pulposus from the herniatedarea 18c can fill and thereby contract away from nerve root 18e. Firstoptical guiding means 116 along with first introducer means 110 areremoved from cannula 104 when the vaporization step is complete.

According to the invention, a second vaporization step is included.According to the preferred embodiment, a second introducer means 130 isinserted into cannula 104 to contact the first vaporized area.

Second introducer means 130 is preferably 14 gauge along its length andhas a 17 gauge tip 130a. Second introducer means 130 is metal,preferably type 304 stainless steel, No. 3 temper (full hard). Moreover,the opening in tip 130a of second introducer means 130 is formeddifferently from first introducer means 110, as illustrated in FIG. 26and in an exploded view illustrated in FIG. 27. Rather than opening130a- 1 being perpendicular to the longitudinal axis of the tubularmember as is shown for first introducer means, opening 130a- 1 at end130a is curved relative to the longitudinal axis. Curved end 130a is notflared out nor wider than the 14 gauge portion of the tubular member. Asa result, curved 13 end 130a of second introducer means 130 need not bewider in diameter than first introducer means 110. In the preferredembodiment, second introducer means 130 is the same inner and outerdiameter as first introducer means 110 and has a curvature at end 130awithin that outer diameter. Therefore, second introducer means 130 fitswithin cannula 104 in the same way first introducer means 110 fitswithin cannula 104. Cannula 104 remains in the patient's body to receivesecond introducer means 130 for the second vaporization step accordingto the preferred embodiment, as described below.

The curved end 130a of second introducer means 130 enters the nucleus18d and contacts the first vaporized area when second introducer means130 is inserted into cannula 104. One end of a second optical guidingmeans 132 is inserted through a central bore 130d, of second introducermeans 130 to emanate from opening 130a-1 into the first vaporized areaat the formed end 130a of second introducer means 130, as illustrated inthe exploded view in FIG. 27. Second optical guiding means 132 has aposition indicator means which is the same as position indicator means111h on first optical guiding means 116. The position indicator means onsecond optical guiding means 132 contacts with clamping means 131 in thesame way as described above for first introducer 110 means and positionindicator means 111h. Clamping means 131 and 111 are essentially thesame and clamping means 131 is illustrated in FIG. 26. When end 132a ofsecond optical guiding means 132 emanates from opening 130a- 1 of curvedend 130a on second introducer means 132, end 132a of second opticalguiding means 132 is deflected off the longitudinal axis of the secondoptical guiding means 132.

The amount which second optical guiding means 132 is deflected isdependent upon the radius of curvature of end 130a of second introducermeans 130. The considerations made when determining what radius ofcurvature to use at least depended on several factors, according to theinvention. First, the minimum radius of curvature should be so formed atthe tip of an introducer means so that the curved introducer means stillfits within cannula 104. Second, optical guiding means 116 or 132, forexample an optical fiber, should deflect with uniform curvature toachieve a minimal loss of laser light guiding efficiency. Third, theradius of curvature of the introducer means allowable and the diameterof the optical guiding means allowable are mutually dependent. Accordingto the preferred embodiment, the radius of curvature is 0.45 whichdeflects second optical guiding means 132 about 17° from thelongitudinal axis when second optical guiding means 132 is a 400 μmoptical fiber. Second optical guiding means 132 can be deflected betweenthe range of 1° to 30° by curved end 130a of second introducer means130, for the preferred embodiment.

Once second optical guiding means 132 is in place and positioned so thatit extends out of curved end 130a of second introducer means 130 for adistance, as predetermined by the surgeon, optical guiding means 132 islocked in place by clamping means 131 in much the same way as describedpreviously for clamping means 111. Therefore, clamping of second opticalguiding means 132 to second introducer means 130 allows second opticalguiding means to be manipulated as second introducer means 130 ismanipulated. An end of second optical guiding means 132 opposite to thedeflected end is attached to a second laser means. Light energy from thesecond laser means is guided by second optical guiding means 132 intothe nucleus 18d to vaporize nucleus pulposus and create a secondvaporized area within nucleus 18d. The second vaporized area 145 of thepreferred embodiment is larger than the first vaporized area and thelarger area is created by the deflected beam emanating from deflectedend 132a of second optical guiding means 132 during this vaporizationstep. Manipulation of second introducer means 130 with second opticalguiding means 132 clamped thereto will cause manipulation of thedeflected beam as well.

According to the invention, when the laser beam is applied generallyalong a line 30-1 to a herniated disc area, the line or path that thelaser beam takes is illustrated by example in FIG. 30A. Line 30-1 isobtained by moving first introducer means 110 having first opticalguiding means 116 disposed therethrough axially within cannula 104.Since laser beams according to the invention are divergent and emanatein a 15° cone from the guiding means, the line or path defined by thedivergent beam is described as a single overall direction the laser beamtravels, as illustrated by arrow A in FIG. 30A. Line 30-2 to a herniateddisc area can also be the path of the laser beam, as illustrated in FIG.30B. Line 30-2 to a herniated disc area is obtained with secondintroducer means 130 having second optical guiding means 132 disposedtherethrough, being deflected off the longitudinal axis by curved end130a. The laser beam guided through deflected second optical guidingmeans 132 is applied along line 30-2.

The laser beam can be applied along a line 31-1, as illustrated in FIG.31A. Line 31-1 is different from line 30-1, as illustrated in FIGS. 30Aand 31A and the difference is at least due to shape of straight firstintroducer means 110 relative to the shape of curved second introducermeans 130. Line 31-1 is obtained by guiding a laser beam along secondoptical guiding means 132 while second optical guiding means 132 isdisposed in curved second introducer means 130.

When the laser beam is applied along line 31-2, line 31-2 is differentfrom line 30-1 and line 30-2, as illustrated in FIGS. 31A and 31B. Line31-2 is obtained by guiding a laser beam along second optical guidingmeans 132 while second optical guiding means is disposed in curvedsecond introducer means 130. Moreover, curved end 130a of secondintroducer means 130 is inserted into cannula 104 at a position rotateda distance from line 30-2. Line 31-2 is at an angle to both line 30-1and line 30-2.

When the laser beam is applied along a line 31-3, line 31-3 is differentfrom line 30-1 and line 30-2, as illustrated in FIG. 31C. Line 31-3 isat an angle to line 30-1 and parallel to line 30-2. Line 31-3 isobtained by guiding a laser beam along second optical guiding means 132while second optical guiding means 132 is disposed in curved secondintroducer means 130 and second introducer means 130 is moved axially adistance within cannula 104 along the path followed by second introducermeans 130 for line 30-2.

According to the preferred embodiment, second introducer means 130having curved tip 130a can be moved axially within cannula 104 while thelaser beam applied to the nucleus from deflected end 132a of secondoptical guiding means is at an angle to the direction of movement.Moreover, second introducer means 130 having second optical guidingmeans 132 disposed therethrough can be rotated to any distance through360° to apply the laser beam in an arc up to 360°. The laser beam fromsecond introducer means 130 can be applied along a plurality of linesthrough 360° or less and each line would be at an angle to the previousline. Second introducer means 130 can be moved axially within cannula104 while being rotated through 360 degrees at least one time andpreferably several times during the second vaporization step. Thedeflected beam from second optical guiding means 132 and the movementincrease the amount of nucleus pulposus vaporized in second vaporizedarea 145. Second introducer means 130 having curved end 130a articulatessecond optical guiding means 132 to increase the amount of nucleuspulposus which can be vaporized. Second introducer means 130 articulatesthe second optical guiding means 132 in a static way because secondintroducer means 130 has one predetermined curved end 130a which willdeflect second optical guiding means 132 in one way and to only onedegree. Different optical guiding means having different radii ofcurvature can be used in addition to second introducer means 130 andstill be within the scope of the invention. On the other hand, variablearticulators are known in the art which articulate optical fibers innumerous ways and to different degrees in endoscopic procedures.Variable or dynamic articulators of the relevant art are much larger indiameter and require much larger paths in which they are manipulated. Asa result, variable articulators are used in endoscopic surgery throughpreexisting body cavities. Second introducer means 130 is a staticarticulator which can be manipulated within much smaller paths than thevariable articulators because of second introducer means 130 design andconstruction. Therefore, static articulator or second introducer means130 of the present invention works well in percutaneous procedures whilevariable articulators do not. Also, second introducer means 130 canvaporize a larger given area than straight first introducer means 110when each is manipulated along the same small path or cannula 104, asdescribed above.

Second optical guiding means 132 can be of the same construction asfirst optical guiding means 116 or can be different. In the preferredembodiment, second optical guiding means 132 is the same construction asthe first optical guiding means, and in particular, can be the sameoptical guiding means used for optical guiding means 116. In the firstembodiment, an optical fiber is used as first optical guiding means 116.Optical fiber 117 can be used as second optical guiding means 132 oranother optical fiber can be used. The optical fibers 117a can have thesame construction or can be different. The optical fibers are preferablythe same construction. The optical fibers can be multiuse (reusable) orsingle use (disposable). In the second embodiment, the hollow opticalwaveguide is used as first optical guiding means 110. A hollow opticalwaveguide can be used as second optical guiding means 132, as well, withslight modification to one end of the optical waveguide to adapt it toformed end 130a of second introducer means 130. Nevertheless, theoptical fibers of the first embodiment are preferred over the hollowoptical waveguides for the present invention. Alternatively, one opticalguiding means can be an optical fiber, while the other optical guidingmeans can be an optical wave guide in a third embodiment. The particularoptical guiding means used for the different embodiments will depend onthe laser means which is also used.

First and second laser means can be the same laser or two differentlasers may be used to produce a laser beam for vaporizing nucleuspulposus. According to the present invention, only one laser isnecessary. The laser system used for percutaneous diskectomy accordingto the present invention can emit energy in the temporal continuous modeor pulse mode in the ultraviolet, visible and infrared ranges of theelectromagnetic spectrum. Table I lists the lasers and the associatedwavelengths for use in percutaneous diskectomies according to theinvention. For example, a Nd:YAG laser which emits energy at 1064 nm canbe modified by second harmonic generation to create a laser beam atanother wavelength. In the preferred embodiment, a Nd:YAG laser whichemits light at 1064 nm is coupled with a frequency doubler to generate alaser beam at 532 nm. For the preferred embodiment, a solid state mediais used as a frequency doubler, in particular a potassium, titanylphosphate crystal (KTP), to create a laser system according to thepresent invention which is usable with either laser means or both. Thelaser system of the preferred embodiment, has been used for otherpercutaneous surgical procedures in the areas of gynecology, urology,dermatology, gasteroenterology, otorhinolaryngology, and otherneurosurgeries, but has not been used for applying a laser beam inpercutaneous diskectomies, according to the present invention. The lasersystem of the preferred embodiment is known in the art as KTP/532™Surgical Laser System.

                  TABLE I                                                         ______________________________________                                        LIST OF LASERS FOR USE IN PERCUTANEOUS DISKECTOMY                                                    Wavelength                                                                    (Nanometers or                                         Laser Type             Micrometers)                                           ______________________________________                                        CO.sub.2               10.6 μm                                             CO                     5, 7 μm                                             Erbium: YAG            2.94 μm                                             Holmium: YAG           1950 nm, 2150 nm                                       Krypton                647 nm                                                 Argon                  488 nm, 514.5 nm                                       Dye Lasers             350 nm, 1000 nm                                        Nd: YAG                1320 nm                                                Nd: YAG (frequency doubled)                                                                          532 nm, 660 nm                                         Nd: YAG (frequency tripled)                                                                          354.7 nm, 440 nm                                       Nd: YAG (frequency quadrupled)                                                                       266 nm, 330 nm                                         Tunable Lasers:                                                               Co:MgF.sub.2           1.75 μm, 2.5 μm                                  Ti: Sapphire           660 nm, 990 nm                                         Ti: Sapphire (frequency doubled)                                                                     330 nm, 495 nm                                         Alexandrite            730 nm, 780 nm                                         Alexandrite (frequency doubled)                                                                      365 nm, 390 nm                                         Excimer Lasers:                                                               Xenon Chloride         308 nm                                                 Xenon Fluoride         248 nm                                                 Argon Fluoride         193 nm                                                 Krypton Fluoride       248 nm                                                 ______________________________________                                    

The laser system according to the present invention should be any laserwhich emits laser energy that is absorbed by body tissue. The lasermeans is are preferably one laser system which is used in both the firstand second vaporization steps.

Any laser system used in accordance with the present invention thatemits a laser beam in the ultraviolet or visible range of theelectromagnetic spectrum can be used in conjunction with optical guidingmeans 116 and 132 of the first embodiment, namely an optical fiber. Anylaser system that emits a laser beam in the infrared range of theelectromagnetic spectrum can be used in conjunction with optical guidingmeans 116 and 132 of the second embodiment, namely a hollow opticalwaveguide 118 or 118a. Therefore, the Argon laser for example, orpreferably Nd:YAG laser modified by second harmonic generation will emita laser beam that is conducted by an optical fiber, according to thepresent invention. The CO₂ laser will emit a laser beam that isconducted by a hollow optical waveguide, according to the presentinvention. In the third embodiment, two lasers are used, one laser whichtypically uses an optical fiber to conduct its laser beam and one laserwhich typically uses a hollow optical waveguide to conduct its laserbeam, as described above.

After the second vaporization step according to the preferredembodiment, second optical guiding means 132 and second introducer means130 are removed from cannula 104. In the preferred embodiment, cannula104 is also removed and the entry point through the skin is covered witha sterile bandage. The patient is then allowed to leave the hospital andrecuperate at home under minimal restrictions or requirements.

Alternatively, in a fourth embodiment an irrigation/aspiration cannula150, is inserted into cannula 104 after second introducer means 130 andsecond optical guiding means 132 are removed. Irrigation/aspirationcannula 150 is preferably 15 gauge along its length and has a 17 gaugetip 150a, as illustrated in FIG. 28. Cannula 150 is used to evacuate thesecond vaporization area so that second vaporization area can be furthercleansed in the unlikely event that loose fragments or debris might bepresent. A vacuum suction device is attached to end 150a of cannula 150and the area is aspirated, before cannula 104 is removed.

The means for inserting instrumentation necessary for percutaneousdiskectomy using a laser can be packaged in a kit and sold, for example,for single use or multiple use. The kit may contain probe 100, straightcannula 104, curved cannula 106, first introducer means 110, secondintroducer means 130, stylet 112, cannula 150 and tools such as amarking pen, scalpel with blade, measuring scale and a lockingstabilizer 105. The kit may contain all these items or some of them.Furthermore, optical guiding means 116 and 132 may be included. Thelaser system according to the preferred and exemplary embodiments may besupplied separately.

While the invention has been described in connection with severalexemplary embodiments, it will be understood that many modificationswill be apparent to those of ordinary skill in the art, while stillbeing within the intended scope of the present invention.

What is claimed is:
 1. A method of performing percutaneous diskectomyusing a laser comprising applying a laser beam to a herniated diskhaving a nucleus while deflecting the laser beam away from alongitudinal axis of the laser beam in the nucleus of the disk, saidlaser beam having a wavelength in the range of 350 nanometers through1,000 nanometers.
 2. A method of performing percutaneous diskectomyaccording to claim 1, wherein the wavelength is 647 nanometers.
 3. Amethod of performing percutaneous diskectomy according to claim 1wherein the wavelength is 488 nanometers.
 4. A method of performingpercutaneous diskectomy according to claim 1 wherein the wavelength is532 nanometers.
 5. A method of performing percutaneous diskectomyaccording to claim 1 wherein the wavelength is 354.7 nanometers.
 6. Amethod of performing percutaneous diskectomy according to claim 1wherein the wavelength is 440 nanometers.
 7. A method of performingpercutaneous diskectomy according to claim 1 wherein the wavelength is990 nanometers.
 8. A method of performing percutaneous diskectomyaccording to claim 1 wherein the wavelength is 495 nanometers.
 9. Amethod of performing percutaneous diskectomy according to claim 1wherein the wavelength is 730 nanometers.
 10. A method of performingpercutaneous diskectomy according to claim 1 wherein the wavelength is780 nanometers.
 11. A method of performing percutaneous diskectomyaccording to claim 1 wherein the wavelength is 365 nanometers.
 12. Amethod of performing percutaneous diskectomy according to claim 1wherein the wavelength is 390 nanometers.
 13. A method of performingpercutaneous diskectomy comprising applying a laser beam to a herniateddisk having a nucleus while deflecting the laser beam away from alongitudinal axis of the leaser beam in the nucleus of the disk, saidlaser beam having a wavelength of 5 microns.
 14. A method of performingpercutaneous diskectomy comprising applying a laser beam to a herniateddisk having a nucleus while deflecting the laser beam away from alongitudinal axis of the laser beam in the nucleus of the disk, saidlaser beam having a wavelength of 7 microns.
 15. A method of performingpercutaneous diskectomy comprising applying laser beam to a herniateddisk having a nucleus while deflecting the laser beam away from alongitudinal axis of the laser beam in the nucleus of the disk, saidlaser beam having a wavelength of 1950 nanometers.
 16. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 2115 nanometers.
 17. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 1.75 microns.
 18. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 2.5 microns.
 19. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 10.6 microns.
 20. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 2.94 microns.
 21. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 1320 nanometers.
 22. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 330 nanometers.
 23. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 308 nanometers.
 24. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 266 nanometers.
 25. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 2150 nanometers.
 26. A method ofperforming percutaneous dickectomy comprising applying a laser beam to aherniated disk, having a nucleus, while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 249 nanometers.
 27. A method ofperforming percutaneous dickectomy comprising applying a laser beam to aherniated disk, having a nucleus, while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 193 nanometers.
 28. A method ofperforming percutaneous dickectomy comprising applying a laser beam to aherniated disk, having a nucleus, while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 248 nanometers.
 29. A method ofperforming percutaneous diskectomy comprising applying a laser beam to aherniated disk having a nucleus while deflecting the laser beam awayfrom a longitudinal axis of the laser beam in the nucleus of the disk,said laser beam having a wavelength of 514.5 nanometers.